Importing photos

Hi

I've just bought a new iMac, having been a PC user, and struggling to organise imported photos.

I've copied my pictures folder from my PC onto the iMac and then dragged it into Photos App. However, the nice folder (album) structure I had is not there and all the pictures are dumped into one "All photos" album.

Is there a way to keep my album structure please?

BTW - I also have iphones / ipads that I Sync'd via my PC iTunes which kept this album structure - so not sure what ill no happen when I next Sync from my iMac...

Thanks for your help.